1.Java中使用POI操作ExceL的读与写

​直接给代码

1.1导入依赖

org.apache.poi

poi

3.10-FINAL

org.apache.poi

poi-ooxml

3.10-FINAL

1.2 使用工具类

package cn.Poi;

import cn.domain.Customer;

import org.apache.poi.hssf.usermodel.HSSFRow;

import org.apache.poi.hssf.usermodel.HSSFSheet;

import org.apache.poi.hssf.usermodel.HSSFWorkbook;

import org.apache.poi.ss.usermodel.Row;

import org.apache.poi.ss.usermodel.Sheet;

import org.apache.poi.ss.usermodel.Workbook;

import org.apache.poi.xssf.usermodel.XSSFWorkbook;

import java.io.File;

import java.io.FileInputStream;

import java.io.FileOutputStream;

import java.lang.reflect.Field;

import java.util.ArrayList;

import java.util.List;

public class ExcelUtils {

/**

* 、创建单元格

* @param excelDir 路径

* @param excelFileName 文件名

* @throws Exception

*/

public static void createExcel2007(File excelDir , String excelFileName) throws Exception{

// 1. 内存中创建一个excel工作薄

Workbook wb = new HSSFWorkbook(); //创建了一个2007之前格式的excel文件

// 创建页

createSheet(wb,10);

// 创建行和列

fillData(wb.getSheet("第0页"),10,10);

// 2. 保存这个excel 磁盘上

File excelFile = new File(excelDir,excelFileName);

final FileOutputStream out = new FileOutputStream(excelFile);

wb.write(out);

out.close();

}

/**

* 同上

* @param excelDir

* @param excelFileName

* @throws Exception

*/

public static void createExcel2008(File excelDir , String excelFileName) throws Exception{

// 1. 内存中创建一个excel工作薄

Workbook wb = new XSSFWorkbook();//创建了一个2007之前格式的excel文件

// 2. 保存这个excel 磁盘上

File excelFile = new File(excelDir,excelFileName);

final FileOutputStream out = new FileOutputStream(excelFile);

wb.write(out);

out.close();

}

/**

* 创建文档页码

* @param wb

* @param sheetNum

*/

public static void createSheet(Workbook wb , int sheetNum){

for (int i = 0; i < sheetNum; i++) {

wb.createSheet("第"+i+"页");

}

}

/**

* 创建单元格，并且在里面填充数字进行测试，写入测试

* @param sheet

* @param row

* @param col

*/

public static void fillData(Sheet sheet , int row , int col){

//创建行

for (int i = 0; i < row; i++) {

Row currentRow = sheet.createRow(i);

//每行多少个单元格

for (int i1 = 0; i1 < col; i1++) {

//获取单元格，并且设置单元格里面的值

currentRow.createCell(i1).setCellValue(i*col+i1);

}

}

}

/**、

* 测试读取数字，从第0页开始

* @throws Exception

*/

public static void readExcelint() throws Exception{

FileInputStream excelFile = new FileInputStream("C:/Users\\10596\\Desktop\\firstExcel.xls");

HSSFWorkbook hssfWorkbook = new HSSFWorkbook(excelFile);

final HSSFSheet sheet = hssfWorkbook.getSheet("第0页");

//分别获取 文档中最后一行的行标，单元格

for (int i = 0 ; i

final HSSFRow row = sheet.getRow(i);

for (int j = 0 ; j

double value = row.getCell(j).getNumericCellValue();

System.out.println(value);

}

}

}

/**、

* 测试读取文字，从第0页开始

* @throws Exception

*/

public static void readExcelStr() throws Exception{

FileInputStream excelFile = new FileInputStream("C:/Users\\10596\\Desktop\\customerList.xls");

HSSFWorkbook hssfWorkbook = new HSSFWorkbook(excelFile);

final HSSFSheet sheet = hssfWorkbook.getSheet("第0页");

//分别获取 文档中最后一行的行标，单元格

for (int i = 0 ; i

final HSSFRow row = sheet.getRow(i);

for (int j = 0 ; j

String stringCellValue = row.getCell(j).getStringCellValue();

System.out.println(stringCellValue);

}

}

}

/**

* 写入数据

* @throws Exception

*/

public static void db2excel() throws Exception{

List list = new ArrayList();

for(int i = 0; i < 100; i++){

Customer customer = new Customer();

customer.setId(i+"jack");

customer.setName("jack"+i);

customer.setAddress("测试"+i);

list.add(customer);

}

// 1. 内存中创建一个excel工作薄

Workbook wb = new HSSFWorkbook(); //创建了一个2007之前格式的excel文件

// 创建页

createSheet(wb,10);

// 创建行和列

Field[] declaredFields = Customer.class.getDeclaredFields();

//在第0页填充数据

Sheet sheet = wb.getSheet("第0页");

//获取集合的大小，间接性获取有多少个对象需要存入到文档

for (int i = 0; i < list.size() ; i++){

Customer customer = list.get(i);

//有多少对象就有多少行，创建单元行

Row row = sheet.createRow(i);

int col = 0;

for (Field field : declaredFields) {

//反射的 实体类有 私有属性，进行暴力反射

field.setAccessible(true);

//获取对象里面的值，填充到单元格中

String value = (String) field.get(customer);

row.createCell(col++).setCellValue(value);

}

}

// 2. 保存这个excel 磁盘上

File excelFile = new File("C:\\\\Users\\\\10596\\\\Desktop","customerList.xls");

final FileOutputStream out = new FileOutputStream(excelFile);

wb.write(out);

out.close();

}

public static void main(String[] args) throws Exception {

// createExcel2007(new File("C:\\Users\\10596\\Desktop"),"firstExcel.xls");

// readExcelint(); //读取填充的int数

//填充数据

db2excel();

//读取填充的字符串

readExcelStr();

}

}

1.3 使用写入时创建的实体类

package cn.domain;

public class Customer {

private String id;

private String name;

private String address;

public String getId() {

return id;

}

public void setId(String id) {

this.id = id;

}

public String getName() {

return name;

}

public void setName(String name) {

this.name = name;

}

public String getAddress() {

return address;

}

public void setAddress(String address) {

this.address = address;

}

}

1.4 包结构，以及效果

包结构

写入的效果

读取文档打印的效果

标签：Java,String,poi,ExceL,new,POI,import,public,wb

来源： https://blog.csdn.net/Violet_201903027/article/details/100177857